This invention relates to an inventive blue colorant comprising a chromophore having at least one poly(oxyalkylene) chain attached, through aromatic amino group (or groups), to the 1- position, the 4- position, or both, of an anthraquinone backbone. Such colorants exhibit excellent amine/base stability and thermal stability, effective colorations, excellent low extraction rates, and high lightfastness levels, particularly when incorporated within certain media and/or on the surface of certain substrates, particularly polyesters, polyolefins, and polyurethanes. The poly(oxyalkylene) chain or chains can be conveniently tailored to increase the solubility or compatibility in different solvents or resins thereby permitting the introduction of such excellent coloring chromophores within diverse media and/or or diverse substrates as well as provides a liquid colorant which facilitates handling. Compositions and articles comprising such colorants are provided as well as methods for producing such inventive colorants.
All U.S. patents cited within this specification are hereby incorporated by reference.
There continues to be a need to provide versatile colorants within various applications such that the coloring agent itself exhibits excellent colorations, high thermal stability and amine/base stability, excellent lightfastness, low extraction (or drastic reduction in possibility of removal therefrom via extraction by solvents or like sources), ease in handling, ability to mix thoroughly with other coloring agents and thus to provide effective different hues and tints within or on target substrates, and acceptable toxicity levels. There has been a need to provide improved colorants meeting this criteria for certain thermosets such as polyurethane foam applications, and thermoplastic media, such as polyesters, such that the colorants themselves exhibit excellent compatibility therein (for instance in terms of intrinsic viscosity loss and the other characteristics desired for such plastics as noted above). In particular, such characteristics for polyesters are desired for colorants that absorb, for example, though not necessarily, within the blue portion of the visible spectrum. It is believed and, as noted above, has been determined that such desirable polyester plastic colorations with the characteristics noted above are possible through the addition of certain pendant groups [such as, for example poly(oxyalkylene) groups] to the chromophore backbone which do not act as couplers or color modifiers and thus any chromophore (and resultant hue or tint) may be utilized with the inventive anthraquinone chromophore itself.
Previous coloring agents for such end-uses have included pigments, dyes, or dyestuffs, with each having its own drawback, be it an extraction problem from the finished article, a handling problem during manufacturing due to solid dust particles, or a staining problem, due to the difficulty associated with cleaning coloring agents from manufacturing machinery after colored plastic production, and other like issues. As a result, the application of such pigments, dyes, and/or dyestuffs as colorants within plastics (such as polyesters, polyolefins, polyurethanes, and the like) is greatly limited and far from satisfactory due to such physical limitations. However, the utilization of such colorants is highly desired for the hues and shades they provide within the ultimate thermoplastic and thermoset articles themselves. As a result, there is a clear desire to provide easier to handle, more thermally stable, less extractable, more base/amine stable, more compatible with to-be-colored substrates or resins, easy-to-clean, etc, coloring agents for introduction within thermoplastic and thermoset articles to provide decorative, aesthetic, and other like effects. Facilitating the introduction of such chromophores within such formulations is thus a highly desired target within the colored thermoplastic and thermoset industry, whether it be in terms of handling, thermal stability, extraction, base/amine stability, compatibility, cleaning, or the like.
Attempts to meet this desire have included the introduction of certain standard types of polymeric colorants within plastics (be they thermoplastics or thermoset types). Such colorants are primarily poly(oxyalkylenated) compounds, such as triphenylmethanes (i.e., those found within U.S. Pat. No. 4,992,204, to Kluger et al.) aliphatic amino anthraquinones (i.e., those found within U.S. Pat. No. 4,137,243 to Farmer, and U.S. Pat. No. 4,846,846 to Rekers et al.), and the like; however, they also tend to exhibit certain problems during incorporation into thermosets and/or thermoplastics. In thermosets such as polyurethane foam, many of these previously disclosed compositions, particularly those including the blue triphenylmethane colorants, exhibit discoloration problem in association with the basic catalysts utilized and/or with the high exotherm generated during target foam formation (triphenylmethane moieties of such colorants are susceptible to attack by nucleophilic catalysts and their residues); and for those colorants such as aliphatic amino anthraquinones (for example, Reactint(copyright) Blue X17 from Milliken and Company) are not stable to high TDI index during polyurethane foam formation (active hydrogen sites located on the chromophore have been observed to react with isocyanate groups to alter the shade of product). In thermoplastic compositions such as polyester, many of the previously disclosed compositions, particularly those including triphenylmethanes and/or aliphatic amino anthraquinones, are very unstable at within requisite processing temperature range. As a result, the colorations provided by such polymeric colorants may be reduced in strength or changed in shade under such circumstances. Other types of colorants have been discussed within the prior art, such as azos and diazos, but the specific colorations provided by such compounds are limited to certain hues and their utilization within polyesters is suspect from a number of perspectives (such as toxicity, lightfastness, thermal stability, and the like). There is thus a desire to introduce new types of colorants comprising different types of chromophores for the purpose of providing new, effective, versatile colorants for such myriad end-uses as noted above and that exhibit excellent colorations, extraction, thermal stability, amine/base stability, compatibility with other coloring agents and/or polymer additives and/or substrates/resins/media, as well as low toxicity.
In thermoplastics, particularly polyester, one approach to obtain the desired coloration has been to use difunctional dyes that possess the necessary pendant groups to allow them to be copolymerized, exemplified within U.S. Pat. No. 4,403,092 to Davis et al. Though such a method provides effectively colored thermoplastics with good performance such as excellent extraction (due to the copolymerized nature of the dyes), good lightfastness, and the like, there are many drawbacks to such technology. Primarily, such drawbacks include that the colorants have to be added during the polymerization of polyesters thus the necessity of dedicating a high cost polyester production vessel to color due to the inherent and difficult-to-remedy contamination of the vessel by the colorant (which invariably limits flexibility in manufacturing of resins). Furthermore, another drawback is the necessity of the end user or article manufacturer to store large varieties of colored resins of different shades, thus limits the flexibility and adds cost to the end user. The colorants disclosed, for example within U.S. Pat. No. 4,403,092, are inherently powdered or solid in nature and thus are not suitable for direct addition to the molten plastic during any injection molding step. Such powdered coloring agents are developed solely for actual polymerization within the target resin prior to any molding, injection, and other like process step. Drawbacks, thus, to these powdered types include undesirable dusting, contamination and staining of equipment, clogging (during feeding into the molten resin, for example), and poor control of metering during coloring of the target resin within and/or at the molding machinery. A more versatile colorant providing effective colorations when introduced at different steps during thermoplastic formation is thus highly desirable, particularly if these clean-up and contamination issues can be substantially avoided during utilization thereof. Other less noticeable drawbacks exist for such standard polyester coloring technology; however, these issues clearly show that improvements are highly desired, such as to provide easily handled liquid colorants for polyester which are thermally stable and offer excellent performance in areas such as extraction.
Another approach to coloration of thermoplastics such as polyesters and namely polyethylene terephthalate has been through the use of pigments (Thomas G. Weber, Editor, Coloring of Plastics, John Wiley and Sons, New York, 1979). The use of pigments (either neat or in a liquid dispersion), however, is accompanied by undesirable properties such as opacity, dullness of color, low tinctorial strength, and the like, associated with such pigment compounds and formulations. Also, difficulties in uniformly blending the insoluble pigments with the thermoplastic resin are encountered. In addition, with pigment dispersions, significant issues arise with transportation and storage due to the propensity for settling. Also there are problems with clean-ups due to the propensity of pigments for staining equipment (and possibly the personnel operating such equipment).
Anthraquinone-based colorants have been known in the art for a long period of time and are widely used due to their high color strength, broad range of shades, and many are thermally stable and base stable. More specifically, 1,4-aromatic amino substituted anthraquinone blue colorants such as that shown in Comparative Example 20 [1,4-di-para-anisidino-anthraquinone], below, are known in the art and are disclosed in JP 05,330,254 to Takuma et al., as thermal-transfer recording dyes; and in JP 03,087,754 to Koshida et al., as color toner composition which provides high-quality cyan images with good lightfastness; in GB 1,489,239 and U.S. Pat. No. 3,994,679 to Greenhalgh et al., as disperse dyestuffs for dyeing polyester textiles to give a marine blue shade; in U.S. Pat. No. 3,653,800 to Blackwell to dye cotton or polyester-cotton textiles. However, no teaching or fair suggestion of a polymeric version of such a colorant is known, nor is it taught nor fairly suggested that such a colorant could be used for the coloration of thermoplastics such as PET or PP, or thermosets such as polyurethane. In addition, anthraquinone blue colorants such as 1,4-bis(4-hydroxyphenyl amino)-anthraquinone are disclosed in U.S. Pat. No. 5,200,290, U.S. Pat. No. 4,778,742 and U.S. Pat. No. 4,645727 to Ong et al. Such colorants are to be used in reaction with diethyleneglycol bischloroformate, triethyleneglycol bischloroformate, and the like, to make solid blue polycarbonates, or with glutaryl chloride, adipoyl chloride, and the like, to make solid blue polyesters. The resultant blue polycarbonates or polyesters are then dissolved in isoparaffinic hydrocarbon etc to make blue liquid developer for image printing, or formulated with materials such as styrene-butadiene copolymer by melt blending techniques as blue toner compositions. Although this patent disclosed the blue-colored polyesters, the colorant itself is a solid small molecule and has to be copolymerized with other monomers during the formation of polyesters. Furthermore, there is no fair suggestion of blending 1,4-bis(4-hydroxyphenyl amino)-anthraquinone with polyester or polycarbonate resins to form colored articles. A similar version such as a 1,4-bis(2xe2x80x2,6xe2x80x2-dimethyl-4xe2x80x2-substitutedphenyl amino)-anthraquinone dye was disclosed in U.S. Pat. No. 3,918,976 to Arai et al, to color polyester film as photographic film support. Although the solid dyes were mixed with PET chips and the mixture was kneaded and formed into a film by melt extrusion, and the dyes suggested in U.S. Pat. No. 3,18,976 showed improved sublimation resistance, it still significantly migrated to the surface of PET film and will not be able to use these version of dyes for other applications, particularly packaging et al. Furthermore, no fair mention is made of liquid polymeric derivatives of these colorants, nor is it taught nor fairly suggested that these colorants could be added during the molding step of polyester articles. Additionally, no teaching or fair suggestion of polymeric versions of such colorants with a poly(oxyalkylene) chain (or chains) are known, nor is it fairly taught any such polymeric colorants could be used to color thermosets such as polyurethanes. 1,4-Bis(4-hydroxyphenyl amino)-anthraquinone is also disclosed in JP 05,330,254 to Takuma, for utilization as a heat sensitive sublimation transfer recording cyan dye; in GB 2,071,681 to Whittaker to be dissolved in nonpolar fluorinated organic liquids to color refrigerants, manometer indicator fluids, and the like; and in DE 2,123,454 to Neeff to be used to dye polyamide fibers and textiles. Meanwhile, GB 1,444,716 to Clark briefly mentioned the preparations of dyestuffs which contain mainly 1-hydroxy-4-(4-hydroxyphenylamino)-anthraquinone with by-product 1,4-Bis(4-hydroxyphenyl amino)-anthraquinone as a minor component. As noted above, no fair mention is made of liquid polymeric derivatives of these colorants, nor is it taught nor fairly suggested that these colorants could be added during the molding step of polyester articles. Additionally, no teaching or fair suggestion of polymeric versions of such colorants with poly(oxyalkylene) chain or chains is known, nor is it fairly taught any such polymeric colorants could be used to color thermosets such as polyurethanes.
To date, although some liquid colorants (other than less-than-reliable pigment dispersions) have been developed for such target end-uses, unfortunately, as noted above, they have also exhibited certain limitations. Improvements to such technology, such as a new polymeric liquid blue colorant based on anthranquinone that provides effective colorations for such myriad end-uses as noted above and that exhibit excellent colorations, lightfastness, thermal stability, base stability, compatibility with other coloring agents, and low toxicity, at least, is thus highly desired. Again, to date, there have been no teachings or fair suggestions of such a highly desirable, specific potentially polymeric liquid blue colorant within the pertinent prior art or within the colorant industry itself
It has thus now been determined that poly(oxyalkylene) chains attached, through an aromatic amino group (or groups) to the 1- position, 4- position, or both, of an anthraquinone backbone provides such a needed and highly desired liquid blue colorant, particularly for utilization within thermoplastic and thermoset applications. It is thus an object of the invention to provide such a colorant exhibiting (at least) excellent colorations, low extraction, amine/base stability, thermal stability, and lightfastness within target thermoplastic and/or thermoset articles. Another object of this invention is to provide a blue polymeric colorant having at least one poly(oxyalkylene) chain attached thereto, wherein said polymeric colorant can be tailored for ease of processing, ease of mixing within target plastic media, and provides excellent colorations within the target finished articles. Yet another object of this invention is to provide excellent colorations within liquid compositions (such as inks, and the like) through the utilization of such water-soluble, blue liquid aromatic amino anthraquinone-based polymeric colorants, as noted above.
It is to be understood that the term alkyl as used throughout is intended to encompass any straight or branched alkyl moiety, having anywhere from 1 to 30 carbons therein; the same chain length applies to the term xe2x80x9calkoxyxe2x80x9d as well. Also, the terms substituted phenyl and substituted polyphenyl are intended to encompass any phenyl system having any type of pendant group attached thereto, including, without limitation, alkyl groups, alkylene groups, alcohol groups, ether groups, ester groups, amine groups, amide groups, hydroxyls, and the like. Phenyl is basically an unsubstituted ring system (and thus includes hydrogens only).
The present invention preferably encompasses colorants conforming to the structure of Formula (I) 
wherein A is selected from the group consisting of hydrogen, C1-C8 alkyl, C1-C8 alkoxy, and the structure of Formula (II) 
and B is selected from the group consisting of hydrogene, C1-C8 alkyl, C1-C8 alkoxy, and the structure of Formula (III) 
and wherein at least one of A and B is the structure of Formulas (II) or (III); wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 are the same or different and are selected from the group consisting of hydrogen, C1-C20 alkyl, C1-C20 alkoxy, and Q-E, wherein Q is selected from the group consisting of N, O, S, SO2, SO3, CO2, SO2 N, alkyl, and alkoxy, and E conforms to the structure of Formula (IV)
[polyoxyalkylene constituent]zRxe2x80x2xe2x80x83xe2x80x83(IV)
wherein z is 1 or 2; polyoxyalkylene constituent is selected from the group consisting of at least three monomers of at least one C2-20 alkyleneoxy group, glydicol, glycidyl, or mixtures thereof, monomers of at least one C2-20 alkyleneoxy group, glydicol, glycidyl, or mixtures thereof; and Rxe2x80x2 is selected from the group consisting of hydrogen, C1-20 alkyl, C1-20 alkylester, halo, hydroxyl, thio, cyano, sulfonyl, sulfo, sulfato, aryl, nitro, carboxyl, C1-20 alkoxy, amino, C1-20 alkylamino, acrylamino, C1-20 alkylthio, C1-20 C1-20 alkylsufonyl, C1-20 alkylphenyl, phosphonyl, C1-20 alkylphosphonyl, C1-2 alkoxycarbonyl, and phenylthio; wherein at least one of R1, R2, R3, R4, or R5 is Q-E and/or at least one of R6, R7, R8, R9, or R10 is Q-E. Preferably, Q is O, E is a combination of ethylene oxide and propylene oxide, and z is 1.
More specifically, and preferably, the inventive blue anthraquinone colorant conforms to the structure of (V) 
wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 are the same or different and are selected from the group consisting of C1-20 alkyl, halo, hydroxyl, hydrogen, cyano, sulfonyl, sulfo, sulfato, aryl, nitro, carboxyl, C1-20 alkoxy, and Q-E, wherein at least one of R1, R2, R3, R4, and R5 is Q-E, and/or at least one of R6, R7, R8, R9, or R10 is Q-E, wherein Q is selected from the group consisting of N, O, S, SO2, SO3, CO2, and E is represented by the Formula (VI)
[polyoxyalkylene constituent]zRxe2x80x2xe2x80x83xe2x80x83(VI)
wherein polyoxyalkylene constituent is selected from the group consisting of at least three monomers of at least one C2-20 alkyleneoxy group, glydicol, glycidyl, or mixtures thereof, monomers of at least one C2-20 alkyleneoxy group, glydicol, glycidyl, or mixtures thereof, and Rxe2x80x2 is selected from the group consisting of hydrogen, C1-20 alkoxy, C1-20 alkyl, and C1-20 esters. Compositions comprising such compounds conforming to the broad structure of Formulae (I) and (V) are also encompassed within this invention, particularly those comprising such compounds and other coloring agents and other additives such as antioxidants, UV absorbers, flame retardants, light stabilizers, nucleating and/or clarifying agents, and the like, as liquids or as pellets for further introduction within desired molten thermoplastic formulations; and those compositions comprising such compounds and other coloring agents and other additives such as antioxidants, UV absorbers, flame retardants, light stabilizers, catalysts, surfactants, blowing agents, and the like, to effectuate the formation of thermosets such as polyurethane foams. Methods of making such compositions, particularly thermoplastics, such as PET and polypropylene, and thermosets such as polyurethane foam, comprising such compounds of Formulae (I) and (V), above, are also contemplated within this invention.
The term xe2x80x9cthermoplasticxe2x80x9d is intended to encompass any synthetic polymeric material that exhibits a modification in physical state from solid to liquid upon exposure to sufficiently high temperatures. Most notable of the preferred thermoplastic types of materials are polyolefins (i.e., polypropylene, polyethylene, and the like), polyester (i.e., polyethylene terephthalate, and the like), polyamides (i.e., nylon-1,1, nylon-1,2, nylon-6 or nylon-6,6), polystyrenes, polyurethanes, polycarbonates, polyvinyl halides (i.e., polyvinyl chloride and polyvinvyl difluoride, as merely examples), and the like. Preferred thermoplastics within this invention are polyesters, and most preferred is polyethylene terephthalate.
Such thermoplastic articles include bottles, storage containers, sheets, films, fibers, plaques, hoses, tubes, syringes, and the like. Included within this list would be polyester, polystyrene and other like resinous materials in sheet form which are present within windows for strength and resiliency functions. In such an instance, the inventive colorant compounds would provide or contribute to excellent colorations to such thermoplastic articles for decorative, aesthetic, and/or protective (such as ultraviolet or infrared protection) purposes. Basically, the possible uses for such a low-migratory, thermally stable colorant for such items as thennoplastics (particularly polyesters such as transparent polyethylene terephthalate) is voluminous and cannot easily be enveloped. Other possible end-uses, however, would include within solvent systems, printing inks, within and on textiles (either on or within textiles, fibers, or fabrics) and the like.
Other types of articles contemplated within this invention for the inventive colorant compounds include, again without limitation, thermoplastic articles, such as films, sheets, bottles, containers, vials, and the like. Other colorants may be added to or incorporated therein with such inventive colorant compounds to produce different hues and tints, again for aesthetic, decorative, and/or protective purposes. Ultraviolet absorbers may also be introduced, incorporated, and the like, in order to protect the article or, if in container for, the contents therein. In concert with such an inventive colorant, or combinations of colorants with such an inventive colorant, such UV absorber or absorbers may be added in reduced amounts to provide the desired UV protection level, potentially, due to the inherent protective abilities of the colorant or combination thereof in terms of reducing ultraviolet transmissions (or inversely increasing ultraviolet absorption). Thus, such inventive colorants permit cost reductions (by avoiding the cost of larger amounts of expensive UV absorbers) without sacrificing UV protection.
Such thermoplastic colorants (and other additives) are typically added to such compositions during the injection molding (or other type of molding, such as blow molding), thereof, including, and without limitation, by mixing the inventive liquid colorant with resin pellets and melting the entire coated pellets, or through a masterbatch melting step while the resin and the inventive colorant are pre-mixed and incorporated together in pellet form. Such plastics include, again without limitation, polyolefins, polyesters, polyamides, polyurethanes, polycarbonates, and other well known resins, such as those disclosed within U.S. Pat. No. 4,640,690, to Baumgartner et al., and U.S. Pat. No. 4,507,407, to Kluger et al. under the term xe2x80x9cthermoplasticsxe2x80x9d. Generally, such plastics, including the inventive liquid polymeric colorant, UV absorber, and other potential additives, are formed through any number of various extrusion, etc., techniques, such as those disclosed in the aforementioned U.S. patents. Preferred thermoplastics are polyesters, such as, in one non-limiting embodiment, polyethylene terephthalate. xe2x80x9cPlastic packagingxe2x80x9d thus encompasses containers, sheets, blister packages, and the like, utilized for storage purposes and which include the plastics in any combination as noted above. In addition, these aforementioned U.S. patents also provide the same definition and scope of term xe2x80x9cthermosetsxe2x80x9d as for the inventive coloring applications.
The term xe2x80x9cpure, undiluted statexe2x80x9d as used in conjunction with the inventive colorant compounds indicates that the compounds themselves without any additives are liquid at room temperature or which thus encompasses all types that exhibit viscosities of at most 100,000 cps at room temperature or meet such viscosity limits upon exposure to temperatures of at most about 40xc2x0 C. and which remain within said low viscosity range thereafter for at least 24 hours upon cooling to room temperature. Thus, there is no need to add solvents, viscosity modifiers, and other like additives to the compounds to effectuate such a desirable physical state.
The presence of surfactants, solvents, and the like, may be utilized to alter the solubility, coloring characteristics, and the like, of the ultimate inventive polymeric anthraquinone colorant which would be understood and appreciated by the ordinarily skilled artisan within this particular art.
The colorant compounds of Formulae (I) and (V), above, are, again, liquid in their pure, undiluted state; however, pasty or waxy colorants are also encompassed within this invention, due to their handling improvement over clearly solid colorants of similar structures. In order to effectuate coloring of substrates and media, any other standard colorant additives, such as resins, preservatives, surfactants, solvents, antioxidants, flame retardants, antistatic compounds, antimicrobial agents, and the like, may also be utilized within the inventive colorant compound compositions or methods.